47 Matching Results

Search Results

Advanced search parameters have been applied.

Changes of Well Characteristics in the Hatchobaru Geothermal Field (Japan) by Exploitation of Unit No. 2

Description: The reservoir exploitation for Unit No.2 of the Hatchobaru Power Station accelerated the decline of power output of Unit No.1. For the purpose of understanding the mechanism of this output decline, review of existing data, additional well characteristics tests, well loggings and tracer tests were carried out. The results showed that several production wells for Unit No. 1 significantly reduced their productivity due to the inflow of reinjected waste water and due to pressure interference with production wells for Unit No. 2.
Date: January 1, 1995
Creator: Mimura, T.; Oishi, K.; Ogata, Y.; Tokita, H.; Tsuru, Y. & Matsuda, K.
Partner: UNT Libraries Government Documents Department

Geobotanical Remote Sensing Applied to Targeting New Geothermal Resource Locations in the U.S. Basin and Range with a Focus on Dixie Meadows, NV

Description: This paper presents an overview of the work our collaboration is doing to increase the detailed mapped resource base for geothermal exploration in the Western US. We are imaging several large areas in the western US with high resolution airborne hyperspectral and satellite multispectral sensors. We have now entered the phase where the remote sensing techniques and tools we are developing are mature enough to be combined with other geothermal exploration techniques such as aeromagnetic, seismic, well logging and coring data. The imaging sensors and analysis techniques we have developed have the ability to map visible faults, surface effluents, altered minerals, subtle hidden faults. Large regions are being imaged at reasonable costs. The technique of geobotanical remote sensing for geothermal signatures is based on recent successes in mapping hidden faults, high temperature altered mineralization, clays, hot and cold springs and CO2 effluents the Long Valley Caldera and Mammoth Mountain in California. The areas that have been imaged include Mammoth Mountain and the Long Valley Caldera, Dixie Meadows NV, Fish Lake Valley NV, and Brady Hot Springs. Areas that are being imaged in the summer of 2003 are the south moat of the Long Valley Caldera, Mammoth Mountain western Pickles, Nash, Kasameyer, Foxall, Martini, Cocks, Kennedy-Bowdoin, McKnight, Silver, Potts, flanks, Mono Inyo chain north of Mammoth Mountain in CA, and the Humboldt Block in NV. This paper focuses on presenting the overview of the high-resolution airborne hyperspectral image acquisition that was done at Dixie Meadows NV in August 2002. This new imagery is currently being analyzed and combined with other field data by all of the authors on this paper. Results of their work up until the time of the conference will be presented in papers in the remote sensing session.
Date: January 1, 2003
Creator: Pickles, W. L.; Nash, G. D.; Calvin, W. M.; Martini, B. A.; Cocks, P. A.; Kenedy-Bowdoin, T. et al.
Partner: UNT Libraries Government Documents Department

Geoscience/Engineering Characterization of the Interwell Environment in Carbonate Reservoirs Based on Outcrop Analogs, Permian Basin, West Texas and New Mexico.

Description: The objective of this project is to investigate styles of reservoir heterogeneity found in low permeability pelleted wackestone/packstone facies and mixed carbonate/clastic facies found in Permian Basin reservoirs by studying similar facies exposed in the Guadalupe Mountains. Specific objectives for the outcrop study include construction of a stratigraphic framework, petrophysical quantification of the framework, and testing the outcrop reservoir model for effects of reservoir heterogeneity on production performance. Specific objectives for the subsurface study parallel objectives for the outcrop study.
Date: December 31, 1996
Creator: Lucia, F.J. & Kerans, C.
Partner: UNT Libraries Government Documents Department

Calibration of a neutron log in partially saturated media IV: effects of sonde-wall gap

Description: A gap between a neutron sonde and the wall of a borehole can have a significant effect on the observed count rate. This effect was determined experimentally to be linear with gaps as large as 2.5 cm. The count rate is given by N/sub N/ = K/sub 0/ + K/sub 1/g where K/sub 0/ is the count rate that would be observed at zero gap, and g is the gap. The parameters K/sub 0/ and K/sub 1/ are dependent on both water (ie. hydrogen) content and bulk density. In many situations failure to correct the count rate for this gap effect can result in a significant degradation in the accuracy of the water content calculated from the count rate. In a dry borehole, K/sub 1/ is small at zero formation water content, and increases with formation water content. In a water-filled borehole, K/sub 1/ is large at zero formation water content, and tends to decrease with increasing formation water content, becoming zero, as of course it must, if the formation is pure water. The absolute value of K/sub 1/ increases with increasing density. A representation was determined for K/sub 0/ and K/sub 1/ from experimental data. This representation can be used to adjust the count rate at a given gap to equal its zero-gap value. The accuracy of the zero gap equation can then be recovered.
Date: March 8, 1984
Creator: Axelrod, M.C. & Hearst, J.R.
Partner: UNT Libraries Government Documents Department

Thin films for geothermal sensing: Final report

Description: The report discusses progress in three components of the geothermal measurement problem: (1) developing appropriate chemically sensitive thin films; (2) discovering suitably rugged and effective encapsulation schemes; and (3) conducting high temperature, in-situ electrochemical measurements. (ACR)
Date: September 1, 1987
Partner: UNT Libraries Government Documents Department

Lost circulation technology development status

Description: Lost circulation is the loss of drilling fluid from the wellbore to fractures or pores in the rock formation. In geothermal drilling, lost circulation is often a serious problem that contributes greatly to the cost of the average geothermal well. The Lost Circulation Technology Development Program is sponsored at Sandia National Laboratories by the US Department of Energy. The goal of the program is to reduce lost circulation costs by 30--50% through the development of mitigation and characterization technology. This paper describes the technical progress made in this program during the period April 1991--March 1992. 8 refs.
Date: July 1, 1992
Creator: Glowka, D. A.; Schafer, D. M.; Loeppke, G. E.; Scott, D. D.; Wernig, M. D. & Wright, E. K.
Partner: UNT Libraries Government Documents Department

The Long Valley Well: Phase II operations

Description: Phase II of the Long Valley Exploratory Well was completed to a depth of 7588 feet in November 1991. The drilling comprised two sub-phases: (1) drilling 17-1/2 inch hole from the Phase I casing shoe at 2558 feet to a depth of 7130 feet, plugging back to 6826 feet, and setting 13-3/8 inch casing at 6825 feet, all during August--September 1991; and (2) returning in November to drill a 3.85-inch core hole deviated out of the previous wellbore at 6868 feet and extending to 7588 feet. Ultimate depth of the well is planned to be 20,000 feet, or at a bottomhole temperature of 500{degrees}C, whichever comes first. Total cost of this drilling phase was approximately $2.3 million, and funding was shared about equally between the California Energy Commission and the Department of Energy. Phase II scientific work will commence in July 1992 and will be supported by DOE Office of Basic Energy Sciences, DOE Geothermal Division, and other funding sources.
Date: January 1, 1992
Creator: Finger, J. T.
Partner: UNT Libraries Government Documents Department

FORTRAN algorithm for correcting normal resistivity logs for borehold diameter and mud resistivity

Description: The FORTRAN algorithm described was developed for applying corrections to normal resistivity logs of any electrode spacing for the effects of drilling mud of known resistivity in boreholes of variable diameter. The corrections are based on Schlumberger departure curves that are applicable to normal logs made with a standard Schlumberger electric logging probe with an electrode diameter of 8.5 cm (3.35 in). The FORTRAN algorithm has been generalized to accommodate logs made with other probes with different electrode diameters. Two simplifying assumptions used by Schlumberger in developing the departure curves also apply to the algorithm: (1) bed thickness is assumed to be infinite (at least 10 times larger than the electrode spacing), and (2) invasion of drilling mud into the formation is assumed to be negligible.
Date: unknown
Creator: Scott, J.H.
Partner: UNT Libraries Government Documents Department

Numerical modeling and interpretation of dipole-dipole resistivity and IP profiles Cove Fort-Sulphurdale KGRA, Utah

Description: The Cove Fort-Sulphurdale Known Geothermal Resource Area (KGRA) is located near the junction of the Pavant Range and the Tushar Mountains in south-central Utah. The area has been the site of an intensive geothermal exploration effort since 1975. The electrical resistivity data obtained by Union Oil Company and a subsequent survey conducted for the Earth Science Laboratory and a detailed numerical interpretation of both data sets are presented. The detailed modeling permits a characterization of the intrinsic electrical resistivity to depths exceeding 2000 feet. An area of over two square miles with bulk in-situ resistivities of four-to-five ohm-m is delineated at Sulphurdale near the Union Oil Co. well CFSU No. 42-7. The low-resistivities rocks define the area of extensive hydrothermal alteration in response to the presence of clay minerals and conductive thermal fluids. In contrast the area north and east of Cove Fort is typified by high (100-300 ohm-m) resistivities to depths exceeding 2000 feet. This is an area of Cretaceous and Paleozoic sedimentary rocks where two attempts to drill to reservoir depth failed because of extreme drilling problems. The high resistivities are not considered encouraging for the presence of a deeper reservoir. The electrical resistivity interpretation has defined several areas of probable upward migration of thermal fluids along north-trending normal faults. Some of these areas may have potential for direct heat geothermal utilization.
Date: December 1, 1979
Creator: Ross, H. P.
Partner: UNT Libraries Government Documents Department

Magnetic induction technique for mapping vertical conductive fractures: status report

Description: Fracture mapping plays a vital role in the production of energy from hot dry rock. Many fracture mapping techniques are summarized, and their merits discussed. Of these methods, one based on magnetic induction appears to be well suited for the hot dry rock application. As of August 1977, the status is given here of the development of a fracture mapping instrument using magnetic induction. The basic analysis and electronic design have been completed. Detailed mechanical design and fabrication remain.
Date: December 1, 1977
Creator: Landt, J.A.; Rowley, J.C.; Neudecker, J.W. & Koelle, A.R.
Partner: UNT Libraries Government Documents Department

Shallow subsurface temperatures and some estimates of heat flow from the Colorado Plateau of northeastern Arizona

Description: Temperature data to depths of a few hundred meters were obtained from 29 wells in northeastern Arizona; 12 in the region surrounding the San Francisco Volcanic Field, 8 in the Black Mesa area, and 9 in the south-central Colorado Plateau which includes the White Mountains. Although there was evidence for local hydrologic disturbances in many temperature profiles, most wells provided an estimate of the conductive thermal gradient at the site. A few thermal conductivities were measured and were combined with published regional averages for the north-central part of the Colorado Plateau to produce crude estimates of regional heat flux. None of the wells was accessible below the regional aquifers. To these depths, heat flow in the area of the San Francisco Volcanic Field appears to be controlled primarily by regional lateral water movement having a significant downward vertical component of velocity. The mean heat flow of 27 +- 5 mWm/sup -2/ is only a third to a quarter of what we would expect in this tectonic setting. The heat that is being carried laterally and downward probably is being discharged at low enthalpy and low elevation in springs and streams of the Colorado Plateau and Mogollon Rim. In the vicinity of Black Mesa, heat-flow averages about 60 mWm/sup -2/, characteristics of the coal interior of the Colorado Plateau. North of the White Mountain Volcanic Field, the average heat flow is about 95 mWm/sup -2/.
Date: January 1, 1982
Creator: Sass, J.H.; Stone, C. & Bills, D.J.
Partner: UNT Libraries Government Documents Department

High-temperature logging for basic development of HDR reservoirs

Description: The second phase of the Hot Dry Rock (HDR) Geothermal Development Program at Fenton Hill, New Mexico, consists of two boreholes, directionally-drilled in a northeast direction, inclined at an angle of 35/sup 0/, with a vertical separation of 365 m (1200 ft). The two boreholes will be connected by 12 to 15 vertical parallel fractures to make a geothermal reservoir calculated to produce 20 MW(e) for 20 years. Accurate temperature measurements, borehole caliper logs, and directional surveys are required for the successful development and operation of this man-made system. Obtaining these data is extremely difficult because of the bottom hole static temperature of 335/sup 0/C (635/sup 0/F) at a depth of 4660 m (15,289 ft), the 35/sup 0/ deviation, the abrasive formation, and the presence of sticky drilling residue products. The efforts during July, August, and September 1980, to obtain these data are presented as a case history. The temperature logs and borehole directional survey produced realistic results; but the borehole caliper measurements were inconsistent and unreliable, due to the developmental stage of the caliper tools.
Date: January 1, 1981
Creator: Mathews, M.; Pettitt, R.A. & Miles, D.J.
Partner: UNT Libraries Government Documents Department

Acoustic radiation patterns for borehole sources

Description: Amplitudes of S and P waves from commercial borehole acoustic logging tools depend on the angle between the borehole axis and the direction of propagation as well as the distance between source and receiver. Knowledge of the angular dependence or radiation pattern, is necessary to properly measure the attenuation of waves traveling between two boreholes. Functional expressions are shown for the S and P-waves amplitudes. Experimental work in relatively homogeneous granite suggests that this relationship adequately describes the radiation pattern for both explosive sources and for acoustic transducers placed in fluid filled boreholes. Using these functional expressions for the S and P-wave amplitudes a technique was developed to estimate Q, the quality factor, and locate discrete fractures in crystalline rock that compose the Hot Dry Rock Geothermal Reservoir at Fenton Hill, New Mexico.
Date: January 1, 1981
Creator: Fehler, M. & Pearson, C.F.
Partner: UNT Libraries Government Documents Department

LASL hot dry rock geothermal energy development project

Description: The history of the hot-dry-rock project is traced. Efforts to establish a two-hole and connecting fracture system on the southwest flank of the Valles Caldera in north-central New Mexico are summarized. Problems encountered in drilling and hydraulic fracturing are described. Current results with the loop operation for heat extraction are encouraging, and plans for a second energy extraction hole are underway. (JBG)
Date: January 1, 1978
Creator: Hill, J.H.
Partner: UNT Libraries Government Documents Department

Induced-polarization measurements at Roosevelt Hot Springs Thermal area, Utah

Description: An induced polarization survey was conducted at Roosevelt Hot Springs, using the dipole-dipole array. The survey consisted of two profile lines, one across the southern end of the system (2200N) and another across the northern portion (5950N). A total of 15 line-km of profiles was run, with 100 m and 300 m dipoles out to n spacings of 4 to 6. Apparent resistivity amplitude and phase data were gathered with a phase-sensitive receiver at frequencies between 32 Hz and 1/256 Hz. The data are presented in the form of apparent resistivity of phase pseudosections. Induced polarization effects in geothermal environments can result from clays and pyrite which are associated with hydrothermal alteration. Laboratory measurements on altered material show some induced polarization effects at frequencies below 1 Hz which are thought to be due to pyrite. A higher frequency polarization (> 1 Hz) is attributed to the effects of clays. The primary purpose of this survey was to investigate the feasibility of mapping clay alteration zones, and separating them from other conductive features, by making use of their polarization characteristics. The field data show some small, low frequency phase anomalies which may be the result of pyrite deposition. The higher frequencies show considerable phase effects, which can be the result of clays, but the effects of electromagnetic coupling have not, as yet, been assessed.
Date: June 1, 1979
Creator: Chu, J.J.; Sill, W.R. & Ward, S.H.
Partner: UNT Libraries Government Documents Department

High temperature testing of the EDCON borehole gravity housing system conducted at Los Alamos National Laboratories, January 12-18, 1986

Description: A series of tests were conducted on the EDCON borehole gravity meter (BHGM) high temperature sonde. The tests were conducted to determine the suitability of this sonde for logging operations in the Department of Energy Salton Trough test well. 1 ref., 3 figs., 4 tabs.
Date: January 1, 1986
Partner: UNT Libraries Government Documents Department

FY 79 Lava Lake Drilling Program: results of drilling experiments

Description: A drilling program was conducted in December 1978 and January and February 1979 to continue the characterization of the solid and liquid rock components of the Kilauea Iki lava lake. Six holes were drilled from the surface and two previously drilled holes were reentered and deepened for the purposes of measuring downhole temperature profiles, recovering samples of solid, plastic, and molten rock, measuring crust permeability, and determining the performance of conventional and special drilling techniques. Conventional HQ-size (3.78 inches diameter) core drilling equipment using water for cooling and cuttings removal was used to successfully drill during initial entry into 1052/sup 0/C formations. Conventional drilling in reentering flow-back rock was less reliable. The specially designed water jet-augmented drag bit or water jet-augmented core bit was needed to drill reliably into the plastic flow-back rock and through liquid rock veins. This document contains the drill performance data which were recorded during drilling in the crust and the plastic and molten rock zones using both conventional and special drilling procedures and equipment.
Date: December 1, 1979
Creator: Neel, R.R.; Striker, R.P. & Curlee, R.M.
Partner: UNT Libraries Government Documents Department

Geothermal down-well instrumentation (during drilling). Final report

Description: The object of the work was to investigate acoustic and electromagnetic telemetry methods which could be used as a basis for geothermal MWD systems. The emphasis has been on methods which employ the drill string and/or the formation surrounding the borehole as a signalling media. The investigations have been confined to the transmission characteristics of these media and have excluded the area of downwell measurements. Work performed includes: laboratory measurement of acoustic attenuation in drill pipe; field measurement of acoustic attenuation in drill pipe; measurements of drill string vibrations (drilling noise) during drilling; evaluation of drill string vibration dampers; modeling of electromagnetic propagation in the borehole region; and field measurements of attenuation of a downwell electromagnetic signal source. (MHR)
Date: June 1, 1979
Creator: Kent, W.H.; Mitchell, P.G. & Row, R.V.
Partner: UNT Libraries Government Documents Department

Geothermal resources Frio Formation, South Texas

Description: A preliminary study of the Frio sand distribution and formation temperatures and pressures was undertaken in order to define prospective areas in which a more detailed reservoir analysis is necessary prior to the selection of a site for a geothermal well. As a result two potential geothermal fairways were identified--one in the south part of the area in Hidalgo, Willacy, and Cameron Counties, and the other in the north part in north-central Nueces County.
Date: January 1, 1975
Creator: Bebout, D.G.; Dorfman, M.H. & Agagu, O.K.
Partner: UNT Libraries Government Documents Department

Heat flow and sub-surface temperatures in the Great Valley, California

Description: The Great Valley of California is located between the Coastal Ranges and the Sierra Nevada and geologically is a structural trough with a thick sequence of sediments. Preliminary investigations of heat flow indicates that this region is characterized by a low-to-normal heat flow of 0.6 to 1.3 HFU. A number of shallow holes for water supply and deep holes for oil and gas exploration have been drilled. Temperature measurements were made in most of these holes. Unfortunately, core and drill cuttings were available from only a few holes for thermal conductivity measurements. Here, three new heat-flow values, a gradient map, and an isotherm map of temperatures at 200 meters are presented.
Date: January 1, 1982
Creator: Wang, J. & Munroe, R.J.
Partner: UNT Libraries Government Documents Department

Fabrication of a 275/sup 0/C geothermal temperature tool

Description: The fabrication of a Prototype 275/sup 0/C Geothermal Temperature Tool is reviewed. This tool fabrication uses hybrid circuits that were developed at Sandia National Laboratories and are now being built at Teledyne Philbrick. To achieve high-temperature operation, the standard military specification hybrid technology was modified in fabrication processes and materials.
Date: January 1, 1981
Creator: Bonn, P.A.
Partner: UNT Libraries Government Documents Department

The US Hot Dry Rock Geothermal Energy Development Program

Description: Recent accomplishments of the program are highlighted by a successful limited term flow test of the Phase 2 reservoir at the Fenton Hill site near Los Alamos. This reservoir connection was established by sidetracking one of the deep wells into hydraulically fractured areas, identified by microseismic data after original fracture attempts failed to connect the two wells. Hydraulic communication was improved by supplemental fracturing. Preliminary testing indicated a reservoir with fracture volume and heat production area surpassing the values from the earlier Phase 1 reservoir. Following completion of the downhole reservoir system, preparations were made for a reservoir-energy-extraction test. This Initial Closed Loop Flow Test (ICFT) was needed to obtain operating characteristics for planning a much longer test for thorough reservoir evaluation. The 30-day ICFT succeeded with final production of about 10 MWt at 192/sup 0/C, while injecting 285 gpm at 4600 psi and producing 206 gpm at 500 psi. The water loss rate and flow impedance were high, 27% and 18 psi/gpm respectively, but were declining. Radioactive tracer tests indicated reservoir volume growth during the experiment which was continuously monitored for acoustic or microseismic activity. Following the flow test, experiments were continued for several months during the venting process. Preparations are now underway for the Long Term Flow Test (LTFT). To understand as much as possible about the Phase 2 reservoir and to demonstrate the commercial feasibility of energy from HDR reservoirs, a flow test of approximately one year's duration is deemed necessary. Part of the preparation for the LTFT is the workover and repair of the production well and the installation of a competent overall flow loop and energy exchange system. 7 refs., 5 figs.
Date: January 1, 1987
Creator: Franke, P.R.
Partner: UNT Libraries Government Documents Department